	PAGE	66,132
;******************************** MATH03.ASM *********************************
LIBSEG           segment byte public "LIB"
		assume cs:LIBSEG , ds:nothing
;----------------------------------------------------------------------------


	extrn	dword_negate:far
comment 
;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -(  MATH   )
; dword_crc - compute 32 bit crc
;  inputs:  ds:si = buffer with data
;           dx,ax = starting crc value (normally 0)
;           cx    = buffer length
;
;  output:  dx,ax
;* * * * * * * * * * * * * *

	public	dword_crc
dword_crc	proc	far
         mov	es,dx
         or     cx,cx
         jz     @@done
@@loop:
         xor    bh,bh
         mov    bl,al
         lodsb
         xor    bl,al
         mov    al,ah
         mov    ah,dl
         mov    dl,dh
         xor    dh,dh
         shl    bx,1
         shl    bx,1
         les    bx,[crc_table+bx]
         xor    ax,bx
         mov    bx,es
         xor    dx,bx
         loop   @@loop
@@done:
	call	dword_negate		;negate dx,ax
	retf
dword_crc	endp	

;  0
crc_table dd     000000000h, 077073096h, 0ee0e612ch, 0990951bah
         dd     0076dc419h, 0706af48fh, 0e963a535h, 09e6495a3h
         dd     00edb8832h, 079dcb8a4h, 0e0d5e91eh, 097d2d988h
         dd     009b64c2bh, 07eb17cbdh, 0e7b82d07h, 090bf1d91h
;  1
         dd     01db71064h, 06ab020f2h, 0f3b97148h, 084be41deh
         dd     01adad47dh, 06ddde4ebh, 0f4d4b551h, 083d385c7h
         dd     0136c9856h, 0646ba8c0h, 0fd62f97ah, 08a65c9ech
         dd     014015c4fh, 063066cd9h, 0fa0f3d63h, 08d080df5h
;  2
         dd     03b6e20c8h, 04c69105eh, 0d56041e4h, 0a2677172h
         dd     03c03e4d1h, 04b04d447h, 0d20d85fdh, 0a50ab56bh
         dd     035b5a8fah, 042b2986ch, 0dbbbc9d6h, 0acbcf940h
         dd     032d86ce3h, 045df5c75h, 0dcd60dcfh, 0abd13d59h
;  3
         dd     026d930ach, 051de003ah, 0c8d75180h, 0bfd06116h
         dd     021b4f4b5h, 056b3c423h, 0cfba9599h, 0b8bda50fh
         dd     02802b89eh, 05f058808h, 0c60cd9b2h, 0b10be924h
         dd     02f6f7c87h, 058684c11h, 0c1611dabh, 0b6662d3dh
;  4
         dd     076dc4190h, 001db7106h, 098d220bch, 0efd5102ah
         dd     071b18589h, 006b6b51fh, 09fbfe4a5h, 0e8b8d433h
         dd     07807c9a2h, 00f00f934h, 09609a88eh, 0e10e9818h
         dd     07f6a0dbbh, 0086d3d2dh, 091646c97h, 0e6635c01h
;  5
         dd     06b6b51f4h, 01c6c6162h, 0856530d8h, 0f262004eh
         dd     06c0695edh, 01b01a57bh, 08208f4c1h, 0f50fc457h
         dd     065b0d9c6h, 012b7e950h, 08bbeb8eah, 0fcb9887ch
         dd     062dd1ddfh, 015da2d49h, 08cd37cf3h, 0fbd44c65h
;  6
         dd     04db26158h, 03ab551ceh, 0a3bc0074h, 0d4bb30e2h
         dd     04adfa541h, 03dd895d7h, 0a4d1c46dh, 0d3d6f4fbh
         dd     04369e96ah, 0346ed9fch, 0ad678846h, 0da60b8d0h
         dd     044042d73h, 033031de5h, 0aa0a4c5fh, 0dd0d7cc9h
;  7
         dd     05005713ch, 0270241aah, 0be0b1010h, 0c90c2086h
         dd     05768b525h, 0206f85b3h, 0b966d409h, 0ce61e49fh
         dd     05edef90eh, 029d9c998h, 0b0d09822h, 0c7d7a8b4h
         dd     059b33d17h, 02eb40d81h, 0b7bd5c3bh, 0c0ba6cadh
;  8
         dd     0edb88320h, 09abfb3b6h, 003b6e20ch, 074b1d29ah
         dd     0ead54739h, 09dd277afh, 004db2615h, 073dc1683h
         dd     0e3630b12h, 094643b84h, 00d6d6a3eh, 07a6a5aa8h
         dd     0e40ecf0bh, 09309ff9dh, 00a00ae27h, 07d079eb1h
;  9
         dd     0f00f9344h, 08708a3d2h, 01e01f268h, 06906c2feh
         dd     0f762575dh, 0806567cbh, 0196c3671h, 06e6b06e7h
         dd     0fed41b76h, 089d32be0h, 010da7a5ah, 067dd4acch
         dd     0f9b9df6fh, 08ebeeff9h, 017b7be43h, 060b08ed5h
;  A
         dd     0d6d6a3e8h, 0a1d1937eh, 038d8c2c4h, 04fdff252h
         dd     0d1bb67f1h, 0a6bc5767h, 03fb506ddh, 048b2364bh
         dd     0d80d2bdah, 0af0a1b4ch, 036034af6h, 041047a60h
         dd     0df60efc3h, 0a867df55h, 0316e8eefh, 04669be79h
;  B
         dd     0cb61b38ch, 0bc66831ah, 0256fd2a0h, 05268e236h
         dd     0cc0c7795h, 0bb0b4703h, 0220216b9h, 05505262fh
         dd     0c5ba3bbeh, 0b2bd0b28h, 02bb45a92h, 05cb36a04h
         dd     0c2d7ffa7h, 0b5d0cf31h, 02cd99e8bh, 05bdeae1dh
;  C
         dd     09b64c2b0h, 0ec63f226h, 0756aa39ch, 0026d930ah
         dd     09c0906a9h, 0eb0e363fh, 072076785h, 005005713h
         dd     095bf4a82h, 0e2b87a14h, 07bb12baeh, 00cb61b38h
         dd     092d28e9bh, 0e5d5be0dh, 07cdcefb7h, 00bdbdf21h
;  D
         dd     086d3d2d4h, 0f1d4e242h, 068ddb3f8h, 01fda836eh
         dd     081be16cdh, 0f6b9265bh, 06fb077e1h, 018b74777h
         dd     088085ae6h, 0ff0f6a70h, 066063bcah, 011010b5ch
         dd     08f659effh, 0f862ae69h, 0616bffd3h, 0166ccf45h
;  E
         dd     0a00ae278h, 0d70dd2eeh, 04e048354h, 03903b3c2h
         dd     0a7672661h, 0d06016f7h, 04969474dh, 03e6e77dbh
         dd     0aed16a4ah, 0d9d65adch, 040df0b66h, 037d83bf0h
         dd     0a9bcae53h, 0debb9ec5h, 047b2cf7fh, 030b5ffe9h
;  F
         dd     0bdbdf21ch, 0cabac28ah, 053b39330h, 024b4a3a6h
         dd     0bad03605h, 0cdd70693h, 054de5729h, 023d967bfh
         dd     0b3667a2eh, 0c4614ab8h, 05d681b02h, 02a6f2b94h
         dd     0b40bbe37h, 0c30c8ea1h, 05a05df1bh, 02d02ef8dh

LIBSEG	ENDS
	end
